Two-piece closure



June 18, 1968 K. R. MCHARDY ETAL 3,388,841

TWO-PIECE CLOSURE Filed Feb. 23, 1967 2 Sheets-Sheet l INVENTOR. KENNETH R. MC HARDY PAUL A. MARCHANT ATTORNEY June 18, 1968 MCHARDY ETAL 3,388,841

TWO-PIECE cnosuma INVENTOR. KENNETH R. MC HARDY PAUL A. MARCHANT ATTORNEY United States Patent 3,388,841 TWO-PIECE CLOSURE Kenneth R. McHardy, Independence, and Paul A. Marchant, Kansas City, Mo., assignors to Rexall Drug and Chemical Company, Los Angeles, Calif., a corporation of Delaware Filed Feb. 23, 1967, Ser. No. 617,900 Claims. (Cl. 222-548) ABSTRACT OF THE DISCLOSURE A multiple piece container and closure for dispensing a commodity from the container when the closure is in an open position. The closure includes a perforated diaphragm attached to the container and covering the open mouth thereof. A cap is rotatably mounted over the diaphragm and flexes the diaphragm inwardly from its normally bowed configuration to an inward position to insure a tight seal between the diaphragm and cap.

In the design and fabrication of containers for holding and dispensing commodities, particularly powdered materials, it is very ditlicult to achieve an effective seal between the container body and the closure. The container body is normally blow molded in a known manner and has an open top through which the commodity is introduced into the container, and then an injection molded closure is attached to the container body and over the open top. Such closures frequently are multiple piece units and are adapted to be rotated to open and close for dispensing the commodity from the container.

If the container body is fabricated from a plastic material, such as polyethylene, polypropylene, polyvinylchloride and the like, the container walls flex due to shaking and pressure changes during shipping of the filled container thereby creating a flow of air out of the container and a sucking of air back into the container when the walls of the container are flexed outwardly. Frequently, the outward flow of air entrains the powdered material from inside the container, thereby carrying the powdered material with the air stream out of the container. This problem is called dusting and results in a container and closure which is covered on the outside with particles of the powdered material (the problem is aggravated by the static charge inherently on the container) which must be wiped off of the package prior to display of the package on the merchandising shelf.

The present invention is directed to a container and closure structure which permits a limited breathing of the container so that the container is not distorted due to atmospheric changes (pressure, temperature) during shipment, but which provides an effective seal between the container and closure and between the multiple parts of the closure to minimize the dusting problem. The closure of the present invention is specifically directed to a rotatable unit which upon rotation opens and closes ports which permit dispensing the commodity from the container. In the design and fabrication of a rotatable closure, it is extremely ditlicult to achieve an effective seal between the rotatable part and other parts of the closure and with the stationary part on the container.

The drawings illustrate the present preferred embodiment of the invention in which:

FIGURE 1 is a top plan view of the closure in the open dispensing position;

FIGURE 2 is a view similar to FIGURE 1 but showing the closure in a closed position;

FIGURE 3 is a cross-section taken on line 33 of FIGURE 1 but showing the closure and container in disassembled condition;

3,383,841 Patented June 18, 1968 FIGURE 4 is a perspective view of the closure in disassembled condition;

FIGURE 5 is a view similar to FIGURE 3 showing the closure in assembled condition on a container;

FIGURE 6 is an enlarged view similar to FIGURE 3 but showing part of the closure assembled to the container;

FIGURE 7 is a view similar to FIGURE 6 but showin g the closure assembled on the container; and

FIGURE 8 is an enlarged view of a portion of FIG- URE 7.

Briefly, the present invention is directed to a plastic closure assembly fabricated from a semirigid, yet flexible and resilient, plastic material, such as polyethylene, polypropylene, polyvinylchloride and the like, which is adapted to be mounted on the upper rim of an openmouth container. The closure assembly includes a resilient plastic diaphragm member which is mounted over and completely covers the open mouth of the container. The diaphragm is normally uniformly bowed outwardly from the mouth of the container along the longitudinal axis of the container and has at least one hole therethrough which hole is located offset from the center of the diaphragm member. The diaphragm has a peripheral skirt which is adapted to mount the diaphragm on the rim of the open-mouth container. Of course, the diaphragm can mount on the container with a plug type assembly that is, the diaphragm is positioned inside the mouth of the container and a U-shaped peripheral rim is provided on the diaphragm to attach the diaphragm Within the mouth of the container. The specific mode of attaching the diaphragm to the container rim is of less significance than other features of the invention except to the extent discussed later herein.

The closure assembly includes a cap which is mounted on the diaphragm and has an opening therethrough. The cap opening is located offset from the center of the cap so that this opening can be aligned with the hole in the diaphragm upon rotation of the cap relative to the diaphragm and container. A plurality of holes and openings can be provided in the cap and the diaphragm respectively. The holes must align with the openings upon rotation of the cap so that the commodity within the container can be dispensed through the aligned holes and openings. The cap is rotatable relative to the diaphragm and connect-ing means are provided on the diaphragm to unite the cap with the diaphragm.

A significant feature of the present invention is the fact that the diaphragm is bowed outwardly from the mouth of the container. The cap is fabricated from a sufficiently rigid plastic material so that when the cap is mounted on the diaphragm, the diaphragm is then pushed and flexed inwardly to a substantially unbowed position to insure that an effective seal is maintained between the top face of the diaphragm and the under face of the cap.

The plastic material from which the cap and the diaphragm are fabricated has the property of having a memory. Memory is the tendency of a plastic material to return to its original molded shape once a flexing force is removed from it (so long as the flexing force does not permanently distort or stress the plastic material). Thus, since both the diaphragm and the cap unit have a memory the diaphragm tries to resiliently return to its original bowed condition and thus exerts a sealing force to the underside of the cap, and likewise the cap which may be slightly bowed outwardly of the mouth of the container due to the diaphragm pressure, tends to return to its original unbowed condition and maintains a force on the top of the diaphragm to provide an effective seal therewith.

A second significant feature of the present invention is the unitilization of a flexible circumferential wallbetween the central portion of the diaphragm and its point of attachment to the container rim. Thus, when the central diaphragm portion is pushed inwardly by mounting the 7 cap on the diaphragm, the diaphragm is flexed inwardly primarily due to flexure of this thin wall surrounding the central portion of the diaphragm. This results in a minimum distortion of the member used to connect the closure assembly to the container and a minimum distortion of the connecting means between the cap and the diaphragm. If the flexing of the diaphragm when the cap is mounted thereon distorts or affects the connecting means between the cap and the diaphragm, it is necessary to adjust for these features in the fabrication of this unit. This is very diflicult to evaluate and frequently results in overcompensation which adversely affects the capping operation at the filling line. Thus, the assembly of the present invention has been designed and constructed to minimize distortion of the connecting elements of the diaphragm and cap when the cap is rotatably mounted on the diaphragm.

Referring specifically to the drawings, the closure assembly includes a cap 10 and a diaphragm 11. The diaphragm 11 is adapted to be assembled onto the upper rim 12 of an open-mouth container 13. The cap 10 is adapted to be assembled on and to the diaphragm 11 for rotation thereon in a manner to be herein described.

The cap 10 includes a wall 14, having a substantially planar underside 15 and anintegral peripherally depending skirt 16.

The skirt 16 is preferably knurled on its outer surface to provide a gripping surface for the user of the closure assembly, and has an inwardly projecting rib 17 on the inner face of the skirt which is spaced from the underside 15 of the wall 14. The rib 17 engages with a portion of the diaphragm to be described hereinafter.

The cap 10 has a central opening 18 which in the preferred embodiment as shown in the drawings, is in the shape of a five-pointed star. The opening 18 can be in various shapes such as triangular, oval, square, rectangular or the like, so long as a portion of the opening is eccentric to other portions of the opening and portions of the opening are eccentric and olfset from the center of the cap. That is, in the preferred embodiment a portion of the opening is in the form of a star point 19 while the wall portions 20 between the points 19 are located radially inwardly from the point 19. Since the cap 10 rotates about a central axis 21, portions of the wall defining the opening must be at more remote locations (for example, points 19) than other portions of the wall (i.e., portions 20) so that upon rotation of the cap dispensing openings in the underlying wall of the diaphragm 11 may be covered and closed by the wall portions 20. It also appears to be desir able to have the portions 20 extend sufficiently in toward the axis of rotation 21 so that they are not unduly flexed upwardly when the cap member is mounted on the dia phragm member. Thus, the cap must have structural rigidity in the wall 14. If the wall portions 20 are unduly distorted in mounting the cap 10 on the diaphragm 11, the etfective sealing quality of the cap and diaphragm is diminished or lost.

Referring now to the diaphragm 11, the central diaphragm portion 25 is bowed outwardly way from the neck of the container and toward the cap 10 which will be mounted on the diaphragm. In the preferred embodiment the diaphragm is an arc of about a 5.86 radius for a 1.24 diameter diaphragm; which provides about a .030" crown at the middle of the diaphragm. Note the significant differences between the central diaphragm as shown in FIGURE 3 prior to assembly of the cap on the diaphragm and its configuration in FIGURE 5 after the cap 10 has been assembled onto the diaphragm. A downwardly directed wall 26 is integral with the peripheral edge of the central diaphragm portion 25. The lower end of the peripheral wall 26 is joined to a wall 27 which extends radially outwardly and substantially parallel to the central diaphragm wall 25. The wall 27 is substanti ally thinner in cross-section than the central diaphragm wall 25 and the wall 26. Thus, any significant pressures placed on the central diaphragm wall 25 result in a flexing of the wall 27 in a downwardly direction as shown in FIGURES 7 and 8. The thin wall section 27 extends circumferentially around the entire central diaphragm wall 25 and wall 26.

A thickened portion of the wall 27 extends radially outward and joins a peripheral skirt 28 extending downwardly therefrom. Theinnerface of the peripheral skirt 28 has an inwardly directed rib 29 which engages in an undercut portion 30 of a top rim 12 of the container. The rim 12 defines the open mouth of the container. The rib 29 is snapped over the rim 12 and into the undercut portion 30 in assembling the diaphragm member onto the mouth of the container in the manner shown in FIGURES 3 and 5. The undercut portion 30 and the rib 29 are resiliently engaged so that it is diificult to remove the diaphragm from the top of the container.

A continuous upstanding wall 35 is integral with the top surface of wall 27 and slightly spaced from peripheral wall 26. This wall 35 has an outwardly extending rib 36 at its upper end. The wall 35 is quite rigid and yet sufliciently resilient to receive the rib 17 of the cap member 10 as shown in FIGURE 7. Thus, when the cap 10 is snapped onto the diaphragm, the rib 17 snaps beneath the rib 36 as the wall 35 is flexed inwardly (see FIGURES 6 and 7). Thus, the cap 10 is rotatable about axis 21 on top of the diaphragm wall 25 'by'a sliding motion between the inner surfaces of wall 16 and the outer surfaces of wall 35. It should also be noted that when the cap is snapped onto the diaphragm member so that the rib 17 engages beneath the rib 36, the diaphragm wall 25 is pushed downwardly so that it slightly flexes inwardly and the wall 27 is flexed downwardly as shown in FIGURES Z and 8. Thus, the primary flexing force is transmitted from wall 27 (which is thinner than the other Walls). Thus, the assembly of the cap member 10 onto the diaphragm 11 does not distort the connect-ing means 29, 30 between the upper rim of the container and the diaphragm or the connecting means 17, 36 between the cap 10 and the diaphragm 11.

FIGURE 8 shows a slightly modified form of the invention with the majority of the parts as hereinbefore described being the same. However, applicant has slightly modified the structure by increasing the radial extent of the flexible Wall 37 to insure that the force of the cap 10 being assembled onto the diaphragm is at least partly absorbed by a flexure of this wall 37.

While a present preferred embodiment of the invention has been described herein, it may be otherwise embodied within the scope of the following claims.

We claim:

1. A plastic closure assembly adapted to be mounted on an open mouth container comprising:

(a) a resilient plastic diaphragm member positionable over and completely covering the open mouth of the container, said diaphragm being normally bowed outwardly from said mouth and having at least one hole therethrough located offset from the center of the diaphragm;

(b) a peripheral skirt on said diaphragm adapted to mount the diaphragm member on the open mouth container;

(0) an upstanding circumferential rib on said diaphragm, said rib being spaced inwardly of the peripheral skirt on the diaphragm;

(d) a portion of the diaphragm extending between and joining the rib and skirt, said diaphragm portion being engageable with a container rim which defines the open mouth of the container;

(e) a second portion of the diaphragm being located radially inward of said r-ib, said second portion extending circumferentially around the center of the diaphragm and being of lesser thickness than the inside part of the diaphragm so that said inside part can flex inwardly primarily due to distortion of said second portion;

(f) a unit adapted to mount on said diaphragm, said unit including a wall member having an opening therein located at least in part offset from the center of the Wall member the same as the offset of the hole in the diaphragm;

(g) a peripheral skirt on the wall member engageable with said ri-b on the diaphragm to mount the wall member on the diaphragm and permit rotation of the wall member about its center relative to the diaphragm;

(h) said diaphragm peripheral skirt, wall member and diaphragm being so constructed and arranged so that when said wall member is mounted on or overlies the diaphragm, the wall member engages said normally outwardly bowed diaphragm to resiliently flex the diaphragm inwardly toward the open mouth to provide an effective seal between the diaphragm and the wall member;

(i) said wall member being rotatable relative to the diaphragm to a first position to align the holes in each such that a commodity can be dispensed from the container through the aligned holes, and to a second position where the holes are out of alignment to close the container.

2. A plastic closure assembly adapted to be mounted on an open mouth container comprising:

(a) a resilient plastic diaphragm member positionable over and completely covering the open mouth of the container, said diaphragm being normally bowed outwardly from said mouth and having at least one hole therethrough located offset from the center of the diaphragm;

(b) a peripheral skirt on said diaphragm adapted to mount the diaphragm member on the open mouth of the container;

(c) an outlying circumferential portion of' said diaphragm being substantially thinner than the central part of the diaphragm;

(d) connecting means on the diaphragm located radially outside said circumferential portion of the diaphragm;

(e) the central part of the diaphragm being adapted to flex inwardly toward the container mouth by the primarily flexure of said circumferential portion of the diaphragm in the absence of distortion of said connecting means;

(f) a unit adapted to mount on said diaphragm, said unit including a Wall member having an opening therein located at least in part offset from the center of the wall member the same as the offset of the hole in the diaphragm;

(g) the wall member being mountable on said diaphragm connecting means to unite the wall member for rotation about its center relative to the diaphragm;

(h) said connecting means, wall member and diaphragm being so constructed and arranged so that when said wall member is mounted on and overlies the diaphragm, the wall member engages sa-id normally outwardly bowed diaphragm to resiliently flex the central part of the diaphragm inwardly toward the open mouth to provide an effective seal between the diaphragm and the wall member;

(i) said wall member being rotatable relative to said diaphragm to a first position to align the holes in each such that a commodity can be dispensed from the container through the aligned holes, and to a second position where the holes are out of alignment to close the container.

3. A plastic closure assembly adapted to be mounted an open mouth container comprising:

(a) a resilient plastic diaphragm member positionable over and completely covering the open mouth of the container, said diaphragm being normally bowed outwardly from said mouth and having at least one hole therethrough located offset from the center of the diaphragm;

(b) a peripheral skirt on said diaphragm adapted to mount the diaphragm member on the open mouth of the container;

(0) an upstanding rib on said diaphragm concentric with the center of the diaphragm;

(d) a unit adapted to mount on said diaphragm, said unit including a wall member having an opening therein located at least in part offset from the center of the wall member the same as the offset of the hole in the diaphragm, a downwardly directed peripheral skirt on said wall member;

(c) said unit being mounted on the diaphragm with the peripheral skirt of the wall member engaged with the upstanding rib on the diaphragm to unite the unit to the diaphragm and permit rotation of the unit about its center relative to the diaphragm, said rib being snugly and slidably received within said unit skirt;

(f) said rib, wall member, diaphragm and skirt on the wall member being so constructed and arranged so that when said unit is mounted on and overlies the diaphragm, the wall member engages said normally outwardly bowed diaphragm to resiliently flex the diaphragm inwardly toward the open mouth to provide an efiective seal between the diaphragm and wall member; and

(g) said wall member being rotatable relative to the diaphragm to a first position to align the holes in each such that a commodity can be dispensed from the container through the aligned holes and to a second position where the holes are out of alignment to close the container.

4. A plastic closure assembly according to claim 3 wherein:

(a) said wall member has a single central opening extending radially outward to a location offset from the center of the wall member sutficiently to overlie the hole in the diaphragm.

5. A plastic closure assembly according to claim 3 including:

(a) a plurality of holes being located in a circle concentric with the center of the diaphragm;

(b) said wall member having a central opening in a star shape with a plurality of points on the star separated by portions of the wall member located between the points, said points on the star extending outwardly from the center of the wall member at least farther than said concentric circle and said portions of the wall extending inwardly toward the center of the wall member at least farther than said concentric circle; and

(c) the center of said diaphragm and said wall member being identical.

References Cited UNITED STATES PATENTS 2,943,771 7/1960 Driscoll 222548 X 3,276,642 10/1966 Johnson et a1 222-565 X STANLEY H. TOLLBERG, Primary Examiner. 

